Chemotherapy
Chemotherapy is one of the oldest and still one of the most important treatments for leukemia. The word itself often causes fear, but knowing how it works, how it is given and what to expect makes that fear smaller. This topic explains chemotherapy in plain language, without doses or personal schedules, because only your hematology team decides those.
01Short answer
02Simple explanation
The cells in our body divide and renew themselves all the time. Leukemia cells divide very quickly and without control. Chemotherapy medicines act on different stages of cell division and destroy these cells.
The problem is that some healthy cells also divide quickly: blood cells in the bone marrow, the lining of the mouth and gut, and hair roots. That is why blood counts fall during chemotherapy, and mouth sores or hair loss may happen.
In leukemia, several medicines are usually given together. They act on the cell in different ways, so together they work more strongly, and the chance that the leukemia becomes resistant falls.
Treatment is given in cycles: a few days of medicine, then a break of a few weeks. During the break, healthy cells, especially in the bone marrow, recover.
The chemotherapy dose is calculated precisely from a person’s height, weight, test results and general condition. Only the doctor and the clinical pharmacist do this; never change a dose yourself.
03Scientific explanation
How it works: according to NCI, chemotherapy stops or slows the growth of cancer cells, which grow and divide quickly, but it can also harm healthy cells that divide quickly, such as those lining the mouth and intestines and those that make hair grow. Treatment is usually given in cycles so healthy cells can recover during the breaks.
In AML: according to the American Cancer Society, for people who can tolerate intensive treatment, induction often combines cytarabine with an anthracycline (daunorubicin or idarubicin); this schedule is known as “7+3”. Consolidation often uses courses of cytarabine. For people who are not suited to intensive treatment, gentler medicines such as azacitidine or decitabine are used, often together with targeted medicines.
In ALL: according to the American Cancer Society, treatment combines several medicines: vincristine, corticosteroids (prednisone or dexamethasone), anthracyclines, asparaginase, cyclophosphamide, methotrexate, 6-mercaptopurine and cytarabine. Because leukemia cells can “hide” in the brain and spinal fluid, medicines are also given straight into the spinal fluid (intrathecally).
Ways of giving it: according to the American Cancer Society and Cancer Research UK, chemotherapy can be given into a vein (as a drip or injection), by mouth as tablets or capsules, as an injection under the skin or into a muscle, and into the spinal fluid through a lumbar puncture. When frequent and long-term treatment into a vein is needed, a central venous catheter, PICC line or port is placed.
04What happens in the body?
What happens on a treatment day?
Usually a blood sample is taken first, and the doctor checks the results and approves treatment. Anti-sickness medicines are then given, and chemotherapy is given as a drip or an injection. This can take anything from a few minutes to several hours, and sometimes runs continuously day and night. Intensive phases such as induction are often given in hospital.
Why do blood counts fall?
Chemotherapy also temporarily reduces the production of healthy blood cells in the bone marrow. Counts usually reach their lowest point some time after a course and then recover. During this time the risk of infection, bleeding and tiredness is higher, so blood tests are done regularly and transfusions are given when needed.
When to call urgently
If you have a fever, chills, shortness of breath, bleeding that will not stop, vomiting or diarrhea so bad that you cannot keep fluids down, confusion or severe pain, contact your team or emergency services straight away. A fever during neutropenia is an emergency. Ask your team in advance at what temperature you should call.
Safety at home
Chemotherapy medicines can stay in body fluids for a while. Your team will explain simple precautions for your family, such as closing the toilet lid before flushing and washing soiled clothes separately. Keep tablets out of reach of children and do not crush or split them unless your doctor says so.
Other medicines and pregnancy
Some medicines, vitamins and herbal products can change how chemotherapy works, so tell your team about everything you take. Chemotherapy can harm a developing baby, so reliable contraception is important during treatment. If you would like to have children in the future, discuss this before treatment starts.
05How does chemotherapy work?
Four steps from giving the medicine to recovery.
06Chemotherapy groups used in leukemia (simplified)
| Group | Examples | How it acts |
|---|---|---|
| Antimetabolites | Cytarabine, methotrexate, 6-mercaptopurine, fludarabine | Mimic the “building blocks” of DNA and disrupt its assembly |
| Anthracyclines | Daunorubicin, idarubicin, doxorubicin | Damage DNA and stop it from unwinding |
| Vinca alkaloids | Vincristine | Stop the cell’s division “threads” (microtubules) |
| Alkylating agents | Cyclophosphamide, bendamustine | “Stitch” DNA strands to each other |
| Enzymes | Asparaginase | Deprive leukemia cells of an amino acid they need |
| Corticosteroids | Prednisone, dexamethasone | Kill lymphoid leukemia cells |
| Hypomethylating agents | Azacitidine, decitabine | Change the marks that switch genes on and off |
* Which medicines are given, at what dose and in what order is decided only by your hematology team. This table is not a complete list.
07Key terms
- Chemotherapy
- Treatment with medicines that kill rapidly dividing cells.
- Cycle (course)
- Days of treatment followed by a recovery break.
- Combination treatment
- Giving several medicines that act in different ways together.
- Intravenous (IV)
- Giving a medicine directly into a vein.
- Intrathecal
- Giving a medicine into the spinal fluid through a lumbar puncture.
- Anthracycline
- A group of medicines acting on DNA; their effect on the heart is monitored.
- Nadir
- The lowest point of blood counts after a course.
- Neutropenia
- A low level of neutrophils, the cells that fight infection.
- Extravasation
- Leakage of a medicine out of the vein into surrounding tissue.
- Clinical pharmacist
- A specialist who checks doses and medicine interactions.
08Key points
- Chemotherapy targets rapidly dividing cells.
- In leukemia, several medicines are usually given together.
- Treatment is given in cycles with recovery breaks.
- Medicines may go into a vein, by mouth, by injection or into the spinal fluid.
- Blood counts fall for a while.
- A fever during neutropenia is an emergency.
- Tell your team about all the medicines you take.
- Only the doctor sets and changes the dose.
09Frequently asked questions
Does chemotherapy hurt?
Giving the medicine is usually painless. But if you feel burning, pain or swelling at the needle site during a drip, tell the nurse straight away; it may be a sign that the medicine has leaked out of the vein.
Will I definitely lose my hair?
Not everyone, and not with every medicine. Some leukemia medicines cause hair loss and others do not. Even if hair falls out, it usually grows back after treatment ends.
Can I work or go to school during chemotherapy?
It depends on how intensive the treatment is and how you feel. During intensive phases it is often not possible; during gentler phases it sometimes is. Talk it over with your team, bearing infection risk in mind.
What can I eat during chemotherapy?
A balanced diet and enough fluids are important. During neutropenia, food safety needs special attention. Check with your team before starting any diet or vitamin supplements.
How will I know chemotherapy is working?
The response is checked with blood tests and often a bone marrow test. How you feel is not always an accurate guide; discuss the results with your hematologist.
Can I have children after chemotherapy?
Some chemotherapy medicines can affect fertility. It is important to discuss options such as storing sperm or eggs before treatment. Ask your team about this as early as possible.
10Questions for your doctor
Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.
Which chemotherapy protocol will I receive, and how many cycles?
Which side effects are most likely?
Will I be able to stay at home between cycles?
Which medicines and supplements should I avoid during chemotherapy?
12Sources
- National Cancer Institute (NCI). Chemotherapy to Treat Cancer
- National Cancer Institute (NCI). Acute Myeloid Leukemia Treatment (PDQ®) — Patient Version
- National Cancer Institute (NCI). Acute Lymphoblastic Leukemia Treatment (PDQ®) — Patient Version
- American Cancer Society. Chemotherapy
- American Cancer Society. Chemo Infusions or Injections
- American Cancer Society. Chemotherapy Side Effects
- American Cancer Society. Chemotherapy for Acute Myeloid Leukemia (AML)
- American Cancer Society. Chemotherapy for Acute Lymphocytic Leukemia
- Cancer Research UK. Chemotherapy
- Cancer Research UK. How you have chemotherapy
- Cancer Research UK. Side effects of chemotherapy
- NHS (UK). Chemotherapy
- MedlinePlus (U.S. National Library of Medicine). Types of chemotherapy
- Macmillan Cancer Support. Chemotherapy — what it is, types, treatment and side effects